Generally, a vehicle has front seats and rear seats. A passenger vehicle, such as a recreation vehicle, tends to have more rows of seats. These seats include a seat cushion in which a passenger or passengers are seated, and a seat back against which the passenger or passengers rest. In some cases, the seat back provided with a headrest against which the passenger's head rests. The headrest is installed so as to be drawn up from the seat back.
Generally, a seat belt functions to secure a passenger in his or her seat and functions as safety equipment for protecting a driver and a passenger or passengers against the stress which may be due to impact during a car accident, such as rear-end collision, collision, overturn of a car, or a sudden stop of the car.